mirror of https://github.com/bazelbuild/rules_cc
93 lines
3.1 KiB
Python
93 lines
3.1 KiB
Python
|
# Copyright 2024 The Bazel Authors. All rights reserved.
|
||
|
|
#
|
||
|
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
# you may not use this file except in compliance with the License.
|
||
|
|
# You may obtain a copy of the License at
|
||
|
|
#
|
||
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
#
|
||
|
|
# Unless required by applicable law or agreed to in writing, software
|
||
|
|
# distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
# See the License for the specific language governing permissions and
|
||
|
|
# limitations under the License.
|
||
|
|
"""Implementation of the cc_target_capability rule."""
|
||
|
|
|
||
|
|
load(
|
||
|
|
":cc_toolchain_info.bzl",
|
||
|
|
"ArgsListInfo",
|
||
|
|
"FeatureConstraintInfo",
|
||
|
|
"FeatureInfo",
|
||
|
|
"FeatureSetInfo",
|
||
|
|
"TargetCapabilityInfo",
|
||
|
|
)
|
||
|
|
|
||
|
|
def _cc_target_capability_impl(ctx):
|
||
|
|
ft = FeatureInfo(
|
||
|
|
name = ctx.attr.feature_name or ctx.label.name,
|
||
|
|
label = ctx.label,
|
||
|
|
enabled = False,
|
||
|
|
args = ArgsListInfo(
|
||
|
|
label = ctx.label,
|
||
|
|
args = (),
|
||
|
|
files = depset(),
|
||
|
|
by_action = (),
|
||
|
|
allowlist_include_directories = depset(),
|
||
|
|
),
|
||
|
|
implies = depset(),
|
||
|
|
requires_any_of = (),
|
||
|
|
mutually_exclusive = (),
|
||
|
|
external = False,
|
||
|
|
overridable = True,
|
||
|
|
overrides = None,
|
||
|
|
allowlist_include_directories = depset(),
|
||
|
|
)
|
||
|
|
|
||
|
|
# Intentionally does not provide FeatureImplyabilityInfo to prevent
|
||
|
|
# features from implying these kinds of rules.
|
||
|
|
return [
|
||
|
|
ft,
|
||
|
|
FeatureSetInfo(label = ctx.label, features = depset([ft])),
|
||
|
|
TargetCapabilityInfo(label = ctx.label, feature = ft),
|
||
|
|
FeatureConstraintInfo(label = ctx.label, all_of = depset([ft])),
|
||
|
|
]
|
||
|
|
|
||
|
|
cc_target_capability = rule(
|
||
|
|
implementation = _cc_target_capability_impl,
|
||
|
|
provides = [TargetCapabilityInfo, FeatureSetInfo, FeatureConstraintInfo],
|
||
|
|
doc = """A target capability is an optional feature that a target platform supports.
|
||
|
|
|
||
|
|
For example, not all target platforms have dynamic loaders (e.g. microcontroller
|
||
|
|
firmware), so a toolchain may conditionally enable the capabilty to communicate
|
||
|
|
the capability to C/C++ rule implementations.
|
||
|
|
|
||
|
|
```
|
||
|
|
load("//cc/toolchains:toolchain.bzl", "cc_toolchain")
|
||
|
|
|
||
|
|
cc_toolchain(
|
||
|
|
name = "universal_cc_toolchain",
|
||
|
|
# Assume no operating system means no dynamic loader support.
|
||
|
|
enabled_features = select({
|
||
|
|
"@platforms//os:none": [],
|
||
|
|
"//conditions:default": [
|
||
|
|
"//cc/toolchains/capabilities:supports_dynamic_linker",
|
||
|
|
],
|
||
|
|
}),
|
||
|
|
# ...
|
||
|
|
)
|
||
|
|
```
|
||
|
|
|
||
|
|
`cc_target_capability` rules cannot be listed in a
|
||
|
|
[`cc_feature.implies`](#cc_feature-implies) list.
|
||
|
|
|
||
|
|
Note: User-defined capabilities should prefer traditional
|
||
|
|
[user-defined build settings](https://bazel.build/extending/config#user-defined-build-settings).
|
||
|
|
This construct exists to communicate these features to preexisting C/C++ rule
|
||
|
|
implementations that expect these options to be exposed as
|
||
|
|
[features](https://bazel.build/docs/cc-toolchain-config-reference#features).
|
||
|
|
""",
|
||
|
|
attrs = {
|
||
|
|
"feature_name": attr.string(doc = "The name of the feature to generate for this capability"),
|
||
|
|
},
|
||
|
|
)
|